Engine starter



Au@ @9 1929 w. L MGRATH 3,7232@ ENGINE STARTER Original Fled Feb. 3, 1923 2 Sheets-Sheet l v Z] 520 Z Aug. 6, 1929. w. L.. McGRAn-I '1,723,291

ENGINE STARTER Original Filed Feb. 3, 1923 2 Sheets-Sheet 2 Patented Aug. 6, 1929.

UNITED STATES PATENT OFFICE.

WILLIAM L. MCGRTH, 0F ELMIRA, NEW YORK, ASSIGNOR TO ECLIPSE MACHINE COI- IANY, ELMIRA, NEW YORK, CORPORATION OF NEW YORK.

ENGINE STARTER.

Application led February 3, 1923, Serial No. 616,667. Renewed August 31, 1928.

My invention has relation to means for starting or .cranking an engine such as an internal combustion engine and pertains to that part of an engine starter system known as the drive or transmission which transmits the torque of a prime mover such as an electric motor to a part or member of the engine to be started such as the fly-wheel thereof. The object of my invention is to provide a. novel and eiiicient drive or transmission which is capable of manual operation for engagement with the engine member and of automatic disengagement therefrom. Y In the drawings Fig. 1 is an elevation of an engine starter system embodying my invention and illustrating the parts in normal disengaged position; Fig. 2 a sectional elevation of the drive or transmission on a larger scale; Fig. 3 a view similar to Fig. 2 but illustrating the pinion or driving member in disengaged position but with the screw shaft in its shifted position; Figs. 4 and 5 views similar to Fig. 1, but illustrating different positions of the movable parts and Fig. 6 is an enlarged end view of the pinion.

For the purpose of a clearand definite disclosure of my invention I have illustrated one embodiment thereof but it will be understood that such invention may be embodied in structures of somewhat different form and arrangement without departing from the spirit and scope of my invention. It will also be understood that while I have shown such invention as applied to the so-called inboard type of-drive the same may be applied to the outboard type of drive. Further, it will be understood that while I have shown my invention embodied in that type of drive known as the direct drive, in which the drive is connected with the extended armature shaft of an electric motor, my invention is also applicable to the indirect drive in which the vdrive is connected with a counter shaft driven by the armature shaft.

. Referring to the particular embodiment of my invention as illustrated herein, the prime mover is an electric motor 1 provided with an extended armature'shaft 2. This motor is provided with a suitable switch 3 having a movable switch button 4 and the usual electric connections or circuit 5. This shaft is provided at its outer end with enlargements which are formed by a sleeve 6 secured to the shaft 2 in a suitable manner as by means of a pin 7.

- The drive or transmission is formed as an assembly which is applied to and detachable from the extended armature shaft. This assembly comprises a hollow shaft 8 splined to the armature shaft by means of a longitudinal spline or splines 9. This shaft 8 is provided at its middle portion with screw threads 10 and at its inner end with suitable stop means such as a nut 11. Further, this screw shaft at its outer end is provided with or formed as an enlarged head 12 with a circumferential groove 13, to cooperate with the shifting means hereinafter described. It will be understood that the sleeve 6 is not essentially a separate element except where required for assembly purposes. Also, it will be understood that the splines 9 instead of being formed or provided on the armature shaft itself may e carried by a separate sleeve secured to a plain armature shaft.

Upon the screw threaded portion 10 of the shaft 8, there is mounted for longitudinal movement thereof and rotary movement therewith a driving member which is here in the form of a pinion 14. This pinion is adapted to mesh with a. member of the engine to be started, which is here the flyewheel gear 15 of an internal combustion engine.

Suitable means are provided in the screw shaft for holding the pinion in a retracted position with respect thereto as shown in Fig. 3. In the present instance such means consist of a latch 16 adapted to cooperate with the pinion for the purpose stated. This latch is movable in a longitudinal Slot 17 formed in the screw shaft and is pivoted intermediate its length on a cross-pin 18. The latch is spring pressed downwardl as toits outer end by a plunger 19 backs up by a spring 20, which plunger and sprin are 10- ca-ted in a radial chamber 21 in the cad 12. This chamber is closed at its outer end by a screw plug 22. The outer end of the latch therefore tends to move downwardly and its 'inner end upwardly to a position corresponding to the screw threads 10 to thereby engage a longitudinal slot 23 formed in the bore of the pinion as shown in Fig. 6. The tendency of the latch to assume such position is nor mally restrained by the surface 24 formed on the sleeve 6, with the result that when the drive is in normal disengaged position as shown in Figs. 1 and 2, the forward end of the latch is held in inoperative position, that is, entirely below the inside diameter of the screw threads 10. However, when the screw shaft is moved longitudinally inwardl (here towards the right) so that the latch rldes od of the sleeve 6, the spring-pressed plunger 19 will force the outer end of the latch 1nwardly and the forward end thereof outwardly to operative position. When the screw shaft is shifted outwardly longitudinally (here towards the left) the outer curved end of the latch will ride up upon the beveled surface 25 and onto the surface 24 of the sleeve 6.

Between the pinion and the head 12 of the screw shaft there is interposed a coiled torsion spring 26 whose opposite ends 27 and 2,8 are connected respectively with such pinion 14 and head 12.

For manually shifting the drive into engagement with the {1y-wheel, l employ operating connections as illustrated in Figs. 1, 4 and 5. The connections as herein shown comprise a plunger 29, bell crank 30, connecting rod 31 and shifting lever 32, the latter being forked at its lower end to thereby engage the groove 130i the screw shaft. The plunger 29 1s normally upwardly spring-pressed by means of 'the spring 33 and is adapted to be depressed by the hand or foot of the operator.

One arm of the bell crank 30 is located in the path or" movement of the plunger 29 and is adapted to be brought into contact with and to operate the switch button d in the manner shown in Fig. 4i. The bell crank which is here shown mounted upon the motor frame is held in its normal position by the spring 34. The connecting rod 31V is pivotally connected at one end to the bell crank 30 and its other end passes through the lever 32 and is provided with a coiled spring 35 bearing at one end against a nut 36 on such rod and at its other end against the lever 32. A xed collar 37 is provided on the rod 31, the same normally bearing against the lever 32 and adapted to return the latter to normal position. rlhis particular connection-between the rod 31 and lever 32 provides a lost motion spring connection between them to take care of the condition of abutting of the pinion teeth and the ily-wheel teeth it the same should occur.

Describing a cycle of operation, and beginning with the parts in their normal position shown in Fig. 1, the operator or driver depresses the plunger 29 against the tension of its return spring 33, thereby rocking the bell crank from the position shown in Fig. 1 to the position shown in Fig. e. The screw shaft and pinion are now shifted inwardly, that is, to the right and just as the pinion has been fully meshed with the dywheel, the plunger and bell crank actuate the switch button d, whereupon the electric Maasai motor is operated and the y-wheel is rotated by the pinion. The torque of the motor is transmitted from the armature shaft through the splines 9, screw shaft 8 and thence to the pinion 14. The parts are now in the cranking position illustrated in Fig. 4f, at which time the forward or inner end of the latch 16 is in its raised position coincident vwith the screw threads 10.

When the engine operates under its own power, the operator should release the 'clunger 29 so as to permit the drive assembly and operating connections to be restored to normal position. In such restoration of parts, thel demeshing of the pinion from the ilywheel is facilitated in an automatic manner by virtue of its threaded connection with the screw-shaft. However, if the operator should fail to release the plunger 29 immediately upon the starting of the engine, the construction is such that no damage to the drive will result. In such event, the screw shaft will retain its operated or shifted position and the pinion will be automatically demeshed, whereupon the parts will take the position illustrated in Figs. `3 and 5. When the pinion is thus deineshed and screwed backwardly along the screw shaft, the spring 26 by reason of its connection with such pinion and with the screw shaft will be wound up and when the pinion comes within the range o action of the latch 16, such latch will be engaged by the slot 23 in the pinion and such pinion and shaft will be held together for rotary movement in unison. As a result, the pinion is prevented from longitudinal movement as well as from relative rotary movement which the spring 26 tends to cause. Consequently even though the starting motor and the screw shaft are still rotating, it is impossible for the pinion to be advanced longitudinally into mesh again with the iiywheel with the screw shaft in this shifted position. When the operator then releases the plunger 29, the screw shaft will be shifted outwardly to normal position by reason of the spring 34 and when in such longitudinal movement the surfaces 25 and 24 of the sleeve are presented to the outer end of the latch, such latch will be operated to release it from the pinion. yl`he pinion is thereupon permitted to move spirally along the screw shaft towards the right and against the stop nut by reason of the spring 26.

claim:

1. An engine starter drive comprising a rotatable shaft, a sleeve mounted to slide thereon and driven thereby, a driving member mounted upon the exterior of the sleeve or rotary movement therewith and for longitudinal movement thereof and for engagement with a member o the engine to be started, manually operated means rer bodily shifting said sleeve and driving member longitudinally on said rotatable a spring ccnnected to such driving member and sleeve re- 'spectivelyand means dependent upon the relative position of the sleeve and shaft for preventing rotation of the driving member and thereby holding it in a disengaged position after being disengaged from.thc engine member and against the torsional effectof said spring.

2. An engine starter drive comprising a rotatable shaft, a sleeve mounted to sli-de thereon and driven thereby, a driving member mounted upon the exterior of the sleeve for rotary movement therewith and for longitudinal movement thereof and' for engagement with a member of the engine to be started, manually operated means for bodily shifting said sleeve and driving .member longitudinally on said rotatable shaft, a coiled. torsion spring encircling the sleeve and connected at its ends to such driving member and sleeve respectively and means dependent upon the relative position of the sleeve and shaft for preventing rotation of the driving member and thereby holding it in a disengaged position after being disengaged from the engine member and against the torsional effect of said spring.

3. An engine starter drive comprising a rotatable shaft, a screw sleeve mounted to slide thereon and driven thereby, a driving member in the form of a pinion threaded on such sleeve for rotary movement therewith for longitudinal movement thereof and adapted to engage a member of the engine to be started, manually operated means for bodily shifting said sleeve and driving inember longitudinally on said rotatable shaft, a spring connected to such pinion and sleeve respectively and means dependent upon the relative position of the sleeve and shaft for preventing rotation of the driving member and thereby holding it in a disengaged posi- `tion after being disengaged from the engine member and against the torsional effect of said spring.

4. An engine starter drive comprising a rotatable shaft, a screw sleeve mounted to slide thereon and driven thereby, a pinion threaded on the sleeve for rotary movement therewith and for longitudinal movement thereof and adapted to engage a member of the engine to be started, said threads having a relatively short lead, manually operated means for bodily shifting said sleeve and pinion longitudinally on said rotatable shaft, a coiled spring fastened at its ends to the pinion and sleeve respectively, and means for preventing rotation of the pinion and thereby holding it in disengaged position after being disengaged from the engine member and against the torsional effect of Said spring, said means comprising a catch mounted upon the sleeve and adapted to engage the pinion and hold it against rotation when in disengaged position and when the sleeve is in operated position and adapted to be automatically operated by the return movement of such sleeve to thereby release the pinion and permit said spring to rotate it and return 1t to normal position. i

5. An engine starter drive including a bodily-shiftable rotatable element, adapted to be power-rotated, a driving member adapted for engagement with a part of an engine to be driven and mounted on said element for4 rotary movement therewith and longitudinal movement thereof, manually operable means for bodily shifting said element and with it the driving member into position to actuate t-he engine-part, a'torsion spring connected with said element and said driving member and acting to normally position the driving member forwardly on said element, and means for latching said driving member in rearward position on said element and releasing it for spring advancement thereon according to bodily position of said element, said meansbeing rotatable as a Whole with said element.

6. An engine starter drive including a bodily-shiftable rotatable element, adapted to be power-rotated, a driving member adapted for engagement with a part of an engine to be driven and mounted on said element for rotary movement therewith and longitudinal movement thereof, manually operable means for bodily shifting said element and with it the driving member into position to actuate the engine-part, a torsion spring connected with said element and said driving member and acting to normally position the driving member forwardly on said element, and means for latching said driving member in rearward position on said element and releasing it for spring advancement thereon according to bodily position of said element, said means being rotatable as a whole with said element andincluding a catch for engagement with said driving member mounted in a slot in said element.

WILLIAM. L. MOGRATH. 

